Method for Estimating Position of Target by Using Images Acquired from Camera and Device and Computer-Readable Recording Medium Using the Same

1. A method for estimating a position of a target by using an image acquired from a camera, comprising the steps of: (a) setting multiple virtual estimated reference points by dividing a view-path, as a virtual straight path from a geoid to the camera, where the target is located, into a natural number which is 2 or higher number; (b) comparing altitude values of the respective estimated reference points existing between O (x 0 , y 0 , z 0 ) as a point where the view-path and the geoid intersect and C (x n , y n , z n ) as a position of the camera with those of respective points on terrain corresponding to the respective estimated reference points; (c) searching neighboring virtual estimated reference points P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ) among the multiple virtual estimated reference points to satisfy a requirement under which a difference between an altitude z k of one point P k (x k , y k , z k ) among the neighboring estimated reference points and that of the terrain corresponding thereto and a difference between an altitude z k+1 of the other point P k+1 (x k+1 , y k+1 , z k+1 ) among the neighboring estimated reference points and that of the terrain corresponding thereto have different signs; and (d) determining that the actual position of the target exists between the searched estimated reference points P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ).

2. The method of claim 1 , wherein, at the step (d), if there is more than one pair of neighboring estimated reference points that satisfy the requirement at the step (c), it is determined that the actual position of the target exists between a specific pair of neighboring estimated reference points closest from the camera.

3. The method of claim 1 , wherein, at the step (b), upon the comparison between the altitude values of the respective virtual estimated reference points and those of the respective points on the terrain corresponding thereto, altitude values of respective intersecting points where respective virtual vertical straight lines from the respective virtual estimated reference points to the geoid and the terrain intersect are compared with those of the respective estimated reference points.

4. The method of claim 1 , further comprising the step of: (e) setting multiple virtual subdivided reference points by dividing the view-path between P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ) into m which is a number of 2 or higher, and performing operations with the multiple virtual subdivided reference points existing between P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ) similarly to the operations with the multiple virtual estimated reference points existing between O (x 0 , y 0 , z 0 ) and C (x n , y n , z n ) at the steps (b), (c), and (d), to thereby search the actual position of the target between P k1 (x k1 , y k1 , z k1 ) and P k1+1 (x k1+1 , y k1+1 , z k1+1 ).

5. The method of claim 4 , wherein m is set just as same as n.

6. A method of estimating a position of a target from an image acquired from a camera, comprising the steps of: (a) setting multiple virtual estimated reference points by dividing a section between 0 (x 0 , y 0 , z 0 ) as a point where a view-path, as a virtual straight path from a geoid to the camera, on which the target is located and the geoid intersect and B (x n , y n , z n ) as a point on the view-path determined by referring to one of top n altitude values of terrain included in the image among all sections of the view-path into m which is a number of 2 or higher; (b) comparing altitude values of the multiple virtual estimated reference points existing between B (x n , y n , z n ) and O (x 0 , y 0 , z 0 ) on the view-path with those of respective points on the terrain corresponding thereto; (c) searching neighboring virtual estimated reference points P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ) among the multiple virtual estimated reference points to satisfy a requirement under which a difference between an altitude z k of one point P k (x k , y k , z k ) among the neighboring estimated reference points and that of the terrain corresponding thereto and a difference between an altitude z k+1 of the other point P k+1 (x k+1 , y k+1 ) among the neighboring estimated reference points and that of the terrain corresponding thereto have different signs; and (d) determining that the actual position of the target exists between the searched estimated reference points P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ).

7. The method of claim 6 , wherein B (x n , y n , z n ) on the view-path is determined as a point that has z n as the same value as the point selected as one of top n altitude values of the terrain included in the acquired image.

8. A device for estimating a position of a target from an image acquired from a camera, comprising: an estimated reference points-setting part for setting multiple virtual estimated reference points by dividing a view-path, as a virtual straight path from a geoid to the camera, where the target is located, into a natural number which is 2 or higher number; an altitude-comparing part for comparing altitude values of the respective estimated reference points existing between O (x 0 , y 0 , z 0 ) as a point where the view-path and the geoid intersect and C (x n , y n , z n ) as a position of the camera with those of respective points on terrain corresponding to the respective estimated reference points; a target position-determining part for searching neighboring virtual estimated reference points P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ) among the multiple virtual estimated reference points to satisfy a requirement under which a difference between an altitude z k of one point P k (x k , y k , z k ) among the neighboring estimated reference points and that of the terrain corresponding thereto and a difference between an altitude of the other point P k+1 (x k+1 , y k+1 , z k+1 ) among the neighboring estimated reference points and that of the terrain corresponding thereto have different signs; and determining that the actual position of the target exists between the searched estimated reference points P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ).

9. The device of claim 8 , wherein, if there is more than one pair of neighboring estimated reference points that satisfy the requirement, the target position-determining part determines that the actual position of the target exists between a specific pair of neighboring estimated reference points closest from the camera.

10. The device of claim 8 , wherein, upon the comparison between the altitude values of the respective virtual estimated reference points and those of the respective points on the terrain corresponding thereto, the altitude-comparing part compares altitude values of respective intersecting points where respective virtual vertical straight lines from the respective virtual estimated reference points to the geoid and the terrain intersect with those of the respective estimated reference points.

11. The device of claim 8 , wherein the target position-determining part sets multiple virtual subdivided reference points by dividing the view-path between P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ) into m which is a number of 2 or higher, and performs operations with the multiple virtual subdivided reference points existing between P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ) similarly to the operations with the multiple virtual estimated reference points existing between O (x 0 , y 0 , z 0 ) and C (x n , y n , z n ), to thereby search the actual position of the target between P k1 (x k1 , y k1 , z k1 ) and P k1+1 (x k1+1 , y k1+1 , z k1+1 ).

12. The device of claim 11 , wherein m is set just as same as n.

13. A device for estimating a position of a target from an image acquired from a camera, comprising: an estimated reference points-setting part for setting multiple virtual estimated reference points by dividing a section between 0 (x 0 , y 0 , z 0 ) as a point where a view-path, as a virtual straight path from a geoid to the camera, on which the target is located and the geoid intersect and B (x n , y n , z n ) as a point on the view-path determined by referring to one of top n altitude values of terrain included in the image among all sections of the view-path into m which is a number of 2 or higher; an altitude-comparing part for comparing altitude values of the multiple virtual estimated reference points existing between B (x n , y n , z n ) and O (x 0 , y 0 , z 0 ) on the view-path with those of respective points on the terrain corresponding thereto; and a target position-determining part for searching neighboring virtual estimated reference points P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ) among the multiple virtual estimated reference points to satisfy a requirement under which a difference between an altitude z k of one point P k (x k , y k , z k ) among the neighboring estimated reference points and that of the terrain corresponding thereto and a difference between an altitude z k+1 of the other point P k+1 (x k+1 , y k+1 , z k+1 ) among the neighboring estimated reference points and that of the terrain corresponding thereto have different signs and then determining that the actual position of the target exists between the searched estimated reference points P k (x k , y k , z k ) and P k+1 (x k+1 , y k+1 , z k+1 ).

14. The device of claim 13 , wherein B (x n , y n , z n ) on the view-path is determined as a point that has z n as the same value as the point selected as one of top n altitude values of the terrain included in the acquired image.